Safety: Part of Machine Design

International Standards Create More Need to Include Safety Earlier

For machine builders, compliance with U.S., EN and IEC safety standards is becoming the de facto requirement for doing business, and safety now is designed in at the early stages, says Dave Collins, manager, machine safety products, at Schneider Electric (www.us.schneider-electric.com). "That offers less potential for untrained operators to tamper with the safety equipment," he thinks.

International standards organizations are cooperating more to develop consistent global guidelines for safeguarding machines. "Within European law, the supplier/machine builder has the responsibility to deliver new machines that are 'safety-inclusive,'" explains Juergen Bukowski, safety program manager, Sick (www.sick.com). "U.S. law requires employers/users to take their new or already-operated equipment and provide a hazard-free environment, which often means users have to design safety around it."

From a design standpoint, safety standards serve as an important guideline, explains Doug Meyer, solutions marketing manager, Yaskawa Electric America (www.yaskawa.com). "The standards replace much of the subjective interpretation about what is safe with objective criteria," he says.

Safety standards provide criteria for selecting the appropriate approved or certified components, agrees Eric Hollister, product sales engineer, Pilz (www.pilzusa.com). "They offer advice for the entire safety design process, from evaluating the overall risk of a machine or process through design, and all the way to implementation and validation," he says.

Safety StarterThe Contactron "4 in 1" motor starter is rated for safety category 3, SIL 3 and ATEX Zone 2. The motor starter can be installed in industrial machine safety applications of up to safety category 3 per EN951-1. Applications include emergency stop, safety door and light curtains. This product is commonly used in combination with a safety relay to control motors, valves, fans, pumps, actuators and VFDs.Phoenix Contact; 800/322-3225www.phoenixcon.com

Communicating ControllerThe XPSMC safety controller provides the same functionality as multiple safety relays and is an alternative to safety relays and safety PLCs. It reduces panel space and simplifies wiring and is available with either 16 or 32 inputs, and with eight safety outputs. All outputs can be converted into timed outputs. External communication is available via Modbus, CANopen or Profibus.Schneider Electric888/778-2733;www.us.schneider-electric.com

Make Doors SafeThe Multifunctional MGB gate box is a safety switch, bolt and door-locking mechanism in one system and combines all necessary requirements to protect a safety door in accordance with EN ISO 13849 and EN 1088. The core of the modular system is the evaluation module, which is available with and without guard locking. In combination with a handle module and an optional escape release, the MGB protects almost every safety door. Euchner866/547-7206www.euchner.com

Modular Safety ControllerThe Sirius 3RK3 modular safety system combines the simplicity of a safety relay with the sophistication of a fail-safe programmable logic controller. The system's central unit is designed with eight safety-related inputs, one safety-related relay output and one safety-related solid-state output. Users can connect up to seven expansion modules to the central unit for specific application requirements. A non-safety-related DP interface module is available for communication with higher-level controllers via Profibus.Siemens Energy & Automation800/964-4114www.sea.siemens.com